#define _CRT_SECURE_NO_WARNINGS
string solve(string s, string t) {
    // write code here
    vector<int> a, b;
    for (int i = s.size() - 1; i >= 0; i--)
        a.push_back(s[i] - '0');
    for (int i = t.size() - 1; i >= 0; i--)
        b.push_back(t[i] - '0');

    vector<int > ret;
    int tmp = 0;
    int n = max(a.size(), b.size());
    for (int i = 0; i < n; i++)
    {

        if (i < a.size()) tmp += a[i];
        if (i < b.size()) tmp += b[i];
        ret.push_back(tmp % 10);
        tmp /= 10;
    }
    if (tmp)
        ret.push_back(1);
    string ret1;
    for (int i = ret.size() - 1; i >= 0; i--)
    {
        ret1 += (ret[i] + '0');
    }
    return ret1;

}
};